Re: [Perl-workflow-devel] How to get a workflow's possible states?

[Phil R. <phi...@un...>]

Thanks Alejandro - I hadn't thought of extending the
persister, so that's very helpful - and fast.
Cheers, Phil


That's clever, thanks
On 08/09/10 15:33, Alejandro Imass wrote:
> On Wed, Sep 8, 2010 at 7:26 AM, Phil Robinson
> <phi...@un...>  wrote:
>    
>> Hi all
>> Does anyone know if there's a way to get a list of all the possible
>> states a workflow could have?
>>
>>      
> As you suspected there is no method per-se to obtain a wf's states,
> but you wouldn't have to craft your own parser either. Look into
> Config.pm and you could probably get what you need from there.
>
>
>    
>> My app. creates lots of workflows for 'jobs', and can display them in
>> lists. I want to have a
>> way where the user can select which ones they see based on their state.
>>
>>      
> Ok, this requirement makes more sense, and for this you don't need to
> mess with the config. workflow.pm provides a way to extend the
> persister with ExtraData. For example in p2ee we have a workflow inbox
> screen where each user sees a list of workflows she has opened. Here
> is how it works:
>
> <persisters>
>     <persister name="Inventory"
>      class="Workflow::Persister::DBI::ExtraData"
>      dsn="DBI:Pg:dbname=p2ee"
>      user="inventory"
>      password="inventory"
>      date_format="%Y-%m-%d %H:%M"
>      autocommit="1"
>      workflow_table="wf"
>      workflow_sequence="wf_workflow_id_seq"
>      history_table="wf_history"
>      history_sequence="wf_history_workflow_hist_id_seq"
>      extra_table="wf_p2ee"
>      extra_data_field="creator,citho,citho_since"
>      />
> </persisters>
>
> The extra table provides the tie between users and Worflows like so:
>
> CREATE TABLE wf_p2ee(
> -- Attributes --
> workflow_id integer,
> creator text,
> citho text,
> citho_since timestamp,
> memo text,
> state_data text,
>   PRIMARY KEY (workflow_id),
>   FOREIGN KEY (workflow_id) REFERENCES wf (workflow_id));
>
>
> So when users login the get presented a screen with each Workflow, the
> state, "Currently In The Hands Of", since, etc. I use DBIx::Class of
> course but I easily get this list with a View:
>
> CREATE VIEW wf_user AS
> SELECT
>          wf.workflow_id AS id,
>          wf.type AS type,
>          wf_p2ee.memo AS memo,
>          wf.state AS state,
>          wf_p2ee.creator AS creator,
>          wf_p2ee.citho AS citho,
>          wf_p2ee.citho_since AS citho_since,
>          wf.last_update AS last_update
> FROM
>          wf_p2ee JOIN wf ON (wf_p2ee.workflow_id = wf.workflow_id);
>
>
>    
>> So I need a menu where the user can select for display (eg) INITIAL,
>> ORDERED, PROCESSED,
>> FINISHED, DESPATCHED. Of course, I could hardcode it but I'd really like
>> to be able to
>> change the workflow without having to change the code too.
>>
>>      
> No need. From the example above you could do something like:
>
> sub get_open_wfs {
>    my $self = shift;
>    my $c = $self->{c};
>    my $type = $self->{type};
>    my $userid = $c->stash->{userid};
>
>    my @wfs = $c->model('inventory::WfUser')->search(
>      {
>        -and =>  [
>          type =>  { '!=', 'root'},
>          state =>  { '!=', 'CLOSED' },
>          -or =>  [
>            creator =>  $userid,
>            citho =>  $userid
>          ],
>        ],
>      }
>    );
>
>    return \@wfs;
> }
>
>    
>> The only thing I can think of is to create a test workflow, get the
>> initial actions and then recursively
>> run all the actions, gathering up all the states I pass though them, It
>> would be a nightmare
>> though as there are lots of conditions etc.
>>
>>      
>    
>> Come to think of it I could read and parse the xml workflow definition
>> which would be simpler.
>>
>>      
> Yeah, for a list to filter the open workflows by state your oculd do
> that, or tap into the config object. But IMHO you don't really need to
> do any of that, because  with the ideas above you could just use a
> select distinct of the states of the actual open workflows, I mean why
> show the user a filter on states the you have no workflows in those
> states?
>
>
> Best,
> Alejandro Imass
>
>    
>> Any better ideas? TIA Cheers, Phil
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>>      


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